Expected tracking times *Unguided #EXOS2 #TECHNICAL


JB1983
 

Nice setup Chris.  I think I'm going to do the powered USB hub as well.  Makes sense to do so.

Is POTHUB just software?

And also, the cable that goes from the serial port on the pmc8, do you need to go serial to serial, or can you use a serial to USB cable Instead and still have it work with ascom?


 

JB,
 
My Nikon's factory USB cable worked fine, but was shorter than I needed, to reach off-mount.  Main thing is that if you do need to change, be aware that there's some 'proprietary' in that cable.
 
On guidescope choice, yes, definitely a case for ease-of-use - and that 60/280 did take some adjusting-to vs the 50/200, which was much easier to use.  
 
I mentioned telescope focal length, because it's the opposite of what I think you said.  Someone with (say) a 400mm FL has a wide FOV, with correspondingly lower resolution on individual objects.  If you are using (say), 621 or 750mm FL, you have a narrower FOV and correspondingly higher image resolution on what you do see.  Camera pixel size is a factor in this as well.  So... the higher your imaging resolution, the better you need to guide, if you want round stars.  
 
With the 50/200, I had test round-star images up to about 300s, but I did want to see if I could tighten the stars a bit overall, and have an irresistible tinkers urge to see what this little mount can do.  This is all a bit moot, because in my light-polluted skies, I should be using 60-180s tops.  I do have a darker sky site available to me, and will see what lengths work there, a bit later.  With the 60/480, I've done test round-star images up to 900s, but you can see the bloat creeping in, vs. shorter images.  The point of all this fooling around was to push the mount's guiding capability (round stars, fairly tight) out well past what I will actually use, preferably in either site, so when I do go out, reliability isn't an issue. That's been a bit of a 'journey', but so far, so good.  
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Jim Johnston <jtjohnston25@...>
 

Chris,

Your set-up looks familiar...


JB1983
 

Bob, sounds like the experiment was a pretty great success.  I think I may actually just start with a 60mm/230mm or 240mm and go from there. With the guide cameras I'm using, the longer focal length will get me down to about 1:3 ratio so that would be a good starting point.  If I do the 50mm/200mm I'm actually sitting at something like 1:4.2 or so, which still isnt bad, but the other option is defintely better in the long run.

Thanks for the info


JB1983
 
Edited

Can someone please verify, when using ascom and connecting the pmc8 unit to PC, what kind of cable is needed to do so.  Is it serial on the pmc8 to serial port on PC or can you go from the serial port on the pmc8 to USB on PC?

Thanks


 

JB,
 
You need a serial-to-USB connection, with an FTDI chip in the middle.  You may find one piece molded cables that do that, or there's an adapter from Parallax that you'd attach a standard usb cable to.  There are probably a few different solutions that folks here use.  
 
In any case, the FTDI chip - and you do need that - does its magic (making a virtual serial port appear), via a driver that you install on your computer.
 
The good news on the Parallax is that it seems to be utterly reliable.  The bad news is that its packaging is bare-bones and you'll probably want to MacGuyver a shell for it, as well as buy it a cable.  Link's below. 
 
https://www.parallax.com/product/28030
 
 
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Wes Mcdonald
 

JB

Follow Bobs advice.  I fooled around and finally bought the USB to serial from parallax.  I did post a potential total solution ( no need to mcgruber) it but as I said in the post I haven't tested it.  It is ftdi.  The thing that blows up frequently is the serial connector pin out.  If you get the parallax that will not be an issue.

There are USB to serial at TTL levels out there....don't get that.  Make sure it is rs232 levels

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


JB1983
 

Thanks Bob, I had no idea it needed to have the chipset in the cable, I totally would have purchased one without by accident.


Chris Tardif
 

POTHUB is an application that is installed by the ASCOM platform. https://ascom-standards.org/

This is the home of the ASCOM Initiative, a loosely-knit group of astronomy software developers and astronomy device manufacturers devoted to vendor-independent plug-and-play control. ASCOM is a many-to-many and language-independent architecture, supported by most astronomy devices which connect to Windows (and soon Linux and MacOS) computers.The diagram below shows how ASCOM differs from ...
ascom-standards.org


From: MAIN@ESPMC-Eight.groups.io <MAIN@ESPMC-Eight.groups.io> on behalf of JB1983 <capnjake83@...>
Sent: June 13, 2019 2:35 PM
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Expected tracking times *Unguided
 
Nice setup Chris.  I think I'm going to do the powered USB hub as well.  Makes sense to do so.

Is POTHUB just software?

And also, the cable that goes from the serial port on the pmc8, do you need to go serial to serial, or can you use a serial to USB cable Instead and still have it work with ascom?


Chris Tardif
 

Sorry I missed the second part of your question.

 

I have the IEXOS-100...It doesn’t have a serial port.  It as the min-USB port which I use a standard USB cable to connect it to the hub.

 

 

Sent from Mail for Windows 10

 


From: MAIN@ESPMC-Eight.groups.io <MAIN@ESPMC-Eight.groups.io> on behalf of Chris Tardif <christardif@...>
Sent: Thursday, June 13, 2019 3:54:14 PM
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Expected tracking times *Unguided
 
POTHUB is an application that is installed by the ASCOM platform. https://ascom-standards.org/

This is the home of the ASCOM Initiative, a loosely-knit group of astronomy software developers and astronomy device manufacturers devoted to vendor-independent plug-and-play control. ASCOM is a many-to-many and language-independent architecture, supported by most astronomy devices which connect to Windows (and soon Linux and MacOS) computers.The diagram below shows how ASCOM differs from ...
ascom-standards.org


From: MAIN@ESPMC-Eight.groups.io <MAIN@ESPMC-Eight.groups.io> on behalf of JB1983 <capnjake83@...>
Sent: June 13, 2019 2:35 PM
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Expected tracking times *Unguided
 
Nice setup Chris.  I think I'm going to do the powered USB hub as well.  Makes sense to do so.

Is POTHUB just software?

And also, the cable that goes from the serial port on the pmc8, do you need to go serial to serial, or can you use a serial to USB cable Instead and still have it work with ascom?


Wes Mcdonald
 

JB

Hy cow.  You are good to go with a USB cord.  No serial connection.  Whoop!

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


JB1983
 

Wes
 If I'm not mistaken that's only the exos100 that has an actual USB output on the mount,  and not the exos2gt.  Wish it did though 


Wes Mcdonald
 

JB

My bad, thought you had an iexos.  Yep you will need the serial tonusb converter.

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


JB1983
 
Edited

Thanks everyone for the help today, its greatly appreciated.  I would have purchased some stuff that wouldn't have worked if not for you guys.

So what I've gathered today leads me to this configuration, let me know if I'm missing anything:

Scope setup will 

Skywatcher 150PDS
Imaging camera   Nikon D5300
Mount   Exos2GT PMC8
Guide scope 60mm/240mm
Guide camera asi120mini

Imaging camera to USB Hub
Guide camera to USB hub
PMC8 unit to USB hub via serial to USB cable with FTDI chipset
USB hub to PC

Connect PMC 8 to PC via wifi

Use ASCOM and POTHub for PC to mount communications

Stellarium to replace explorestars for mount control, object location and goto

PHD2 for guiding 

And backyard Nikon for camera control 

Then it's just a matter of getting everything to work properly.  I've already watched alot of tutorials on PHD2 and I've used the android version of stellarium but havent used its mount control features.

Thanks again for all the help. I've seriosuly done a ton of research online this past while and some of this information I've never ran into in my travels.  Time to pull the wallet out. Summer is like 2 months long in northern Alberta Haha

Cheers everyone 


Wes Mcdonald
 

JB

Look good with one minor change.  You will connect the ascom to PMC8 via USB not wifi.  You don't need wifi for your setup. 

I am concerned the camera might not like being on a hub....just something I read.  No verification.

If you haven't done it yet your camera attachment to your scope needs a few things.  Also with a newt you will have your camera hanging off to one side of the mount....might make balance sort of funny.  Have you put your camera in your scope and achieved focus?

Regards
Wes

On Thu, Jun 13, 2019 at 7:52 PM JB1983 <capnjake83@...> wrote:

[Edited Message Follows]

Thanks everyone for the help today, its greatly appreciated.  I would have purchased some stuff that wouldn't have worked if not for you guys.

So what I've gathered today leads me to this configuration, let me know if I'm missing anything:

Scope setup will 

Skywatcher 150PDS
Imaging camera   Nikon D5300
Mount   Exos2GT PMC8
Guide scope 60mm/240mm
Guide camera asi120mini

Imaging camera to USB Hub
Guide camera to USB hub
PMC8 unit to USB hub via serial to USB cable with FTDI chipset
USB hub to PC

Connect PMC 8 to PC via wifi

Use ASCOM and POTHub for PC to mount communications

Stellarium to replace explorestars for mount control, object location and goto

PHD2 for guiding 

And backyard Nikon for camera control 

Then it's just a matter of getting everything to work properly.  I've already watched alot of tutorials on PHD2 and I've used the android version of stellarium but havent used its mount control features.

Thanks again for all the help. I've seriosuly done a ton of research online this past while and some of this information I've never ran into in my travels.  Time to pull the wallet out. Summer is like 2 months long in northern Alberta Haha

Cheers everyone 


--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


 
Edited

JB,
 
My guide camera is attached to my hub, and it's fine.  
FWIW, the camera's USB2.  The hub is an Anker AH221 that's attached to the laptop w/USB3.
 
And as Wes said, no wifi.  POTH + the PMC8 driver will connect to the PMC8 via the USB hub. You'll pick a COM port (virtual serial) on the pc via the PMC8 driver confing, once everything is powered and attached. Anything that needs to connect to the PMC8 does it via POTH (your ASCOM hub). 
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Wes Mcdonald
 

JB and Bob

My concern about the hub is the Nikon not the guide camera.

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


JB1983
 

Thanks Bob and Wes.   Big 10-4 on the no wifi. 
I guess I could use the wifi to connect to my home network and remotely control the PC from inside so that's a plus.

I'm going to do the same and use a powered USB 3.0 hub even though everything is usb 2.0

I forgot that stellarium probably needs wifi to sync to my location and time.  


Wes, I actually have but not on this mount yet.  I was using a manual altaz mount and did M42 this past winter.  I achieved focus by using the stars around the object and it worked great.

I dont have a bahnitov mask or anything else at this time so I'm probably going to do the same as I did before.
Slew to the object, find a star or 2 to focus on and go from there.  Downside of using a dslr I guess. I've seen alot of people rotate the scope so the camera is attached underneath at the 6 o clock position but I havent tried that either.


 

JB & Wes,
 
My D5300 is on the hub as well.  It's been fine.  The only issue I had with the camera and USB was getting the right cable with the right length.  
 
Hubs, I just punted and took advice from CN (powered hub, never unpowered) + people seeming happy with the Ankers.  It's just worked.
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


JB1983
 

I did manage to track down the model of cable I need, I'm going to go on a hunt later for a longer version. I forgot how small the supplied one is